Thank you Craig. Every time I read one of your notes it hits me how much I should know that i don't.... (:( Geeta
[EMAIL PROTECTED] wrote on 10/05/2005 03:01:01 PM: > On 10/5/05, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > > > Hubert Rabago <[EMAIL PROTECTED]> wrote on 10/05/2005 02:27:59 PM: > > > > > For your case, initializing an app-wide collection, consider using a > > > ServletContextListener. Even in Struts, this would be recommended for > > > containers that support it. > > > > oh ok I actually know how to do that..;)) Btw, is there some secret reason > > why a listener is better than a plugin..? :) > > > A listener is the right answer to meeting this need. As to the second > question, consider a little bit of history for a moment. Why does Struts > have a plugin architecture in the first place? The answer is that > Struts 1.xwas originally designed to run on top of Servlet > 2.2, which does not have listeners (or even filters). Yet, it was clear that > application startup and shutdown events were a usefu thing to have. > > (Technically, plugins actually have a risk that listeners don't that you > should be aware of. They are implemented by being called from the init() and > destroy() methods of ActionServlet. The risk is that a servlet container is > perfectly free to take an already initialized servlet out of service, > causing the shutdown listeners to be called, even if the application is > still deployed -- which means you might end up paying the initialization > price again on the next request to that servlet. The ServletContextListener > is guaranteed to be called once at app startup time, and once at app > shutdown time, only.) > > Further, there is more than just ServletContextListener (the equivalent of a > Struts PlugIn) available. Consider listeners that implement the following: > > * ServletContextAttributeListener - you get notified any time an application > scope attribute is added, replaced, or removed > > * HttpSessionListener - you get notified when sessions are created or > destroyed > > * HttpSessionAttributeListener - you get notified when a session scope > attribute is added, replaced, or removed > > * ServletRequestListener - you get notified when a request starts or stops > > * ServletRequestAttributeListener - you get notified when a request scope > attribute is added, replaced, or removed > > > > > > Hubert > > > > > > (Can this count as my first answer to a [shale] question? No? Aww.) > > > > Thanks! (and if you answer this question too, it counts...;)) > > Geeta > > > > > There's another message that I'd like to get across here as well. One of the > key reasons that Shale is so small is that it does *not* try to redundantly > implement features supported by the base platform. That's why there is no > "Shale PlugIn" or "Shale Container Managed Security" or things like that. > The underlying platform facilities work just fine, and are recommended for > use. > > Craig > > -- > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed to be clean. > > > CONFIDENTIALITY NOTICE:This email is intended solely for the person > or entity to which it is addressed and may contain confidential > and/or protected health information. Any duplication, > dissemination, action taken in reliance upon, or other use of this > information by persons or entities other than the intended recipient > is prohibited and may violate applicable laws. If this email has > been received in error, please notify the sender and delete the > information from your system. The views expressed in this email are > those of the sender and may not necessarily represent the views of > IntelliCare.
